Automatic starting system



Jan. 19, 1937. 1. E. COFFEY AUTOMATIC STARTING SYSTEM Filed Sept. 24,1954 4 Sheets-Sheet l [k l/EN E COFFEY INVEN TOR.

A TTO RNE Y.

Jan. 19, 1937. COFFEY 2,068,484

AUTOMATIC STARTING SYSTEM Filed Sept. 24, 1934 4 Sheets-Sheet 2 RVEN E.COFFEY //v vsm-ale A TTORNE Y.

Jan. 19, 1937. l E C FFEY 2,068,484

AUTOMATIC S TARTING SYSTEM Filed Sept. 24, 1934 4 Sheets-Sheet 3 F1 G.3. FIG. 4.

6 5a 62 H HHHHH HHHH 6 HHHH 56 FIG. 5. F'IG. 6.

[kl/5N E. COFFEY 11\VENTOR.

ATTORNEY.

Jan. 19, 1937. l. E. COFFEY 2,068,484

AUTOMATI G STARTING SYSTEM Filed Sept. 24, 1954 4 Sheets-Sheet 4 [RI/ENE. COFFEY INVENTOR.

A TTORN E Y.

Patented Jan. 19 1937 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to automatic starting devices for internalcombustion engines, and particularly to the provision of means forcontrolling the supply of current to the starting motor in accordancewith the operating condition of the engine and its various controldevices, such as the ignition switch, accelerator pedaL'etc.

Prior to this invention, devices have been provided for automaticallysupplying current to opcrate the starting motor when the ignitionswitchwas turned on or when the accelerator pedal was depressed andthese devices were in some cases provided with means for discontinuingthe supply of current to the starting motor when the engine began to rununder its own power. These devices, however, have not been entirelysatisfactory in operation, due to various defects in principle and inconstruction, and it is the object of this invention to provide a newand generally improved and simplified control device for governing thesupply of current to the starting motor in accordance with the need forits operation.

The invention will be fully understood from the following descriptionand accompanying drawings, referring to which;

Figure 1 is a diagram of a control system embodying a preferred form ofmy invention;

Figure 2 is a diagram showing a system embodying the invention in asomewhat simplified form.

Figure 3 is a detail view showing a longitudinal cross section of thesuction-influenced relay switch.

Figure 4 shows the same device as Figure 3, but with the parts in adifferent operating position.

Figure 5 is an end view of the device shown in Figures 3 and 4.

Figure 6 is a wiring diagram of the device shown in Figures 3, 4 and 5.

Figure 7 is a detail sectional view of a speed responsive device forcutting off the supply of current to the starting motor.

Figure 8 is an'end view of the device shown in Figure 7.

Figure 9 is a sectional diagram of the speed responsive device takenalong the lines 9-9 of Figure 7.

Figure 10 is a detail sectional view showing parts of the speedresponsive device in the high speed operating position.

The reference numeral I indicates an internal 55 combustion enginehaving a. crank shaft 2, an

intake manifold 3, and a generator 5. The generator is driven by anysuitable means, such for instance as a belt 6 driven by a pulley Imounted on the crank shaft and passing over the'pulley- 8 mounted on thegenerator shaft 9. The gen- 5 erator may be provided with field coils I0and outlet brushes II and 2, the latter being grounded and the formerbeing connected to the reverse current relay switch indicated at l3.This is the device ordinarily mounted on the generators of automotiveinternal combustion engines for the purpose of preventing the flow of aheavy current from the battery to the generator when the generatorvoltage is below that of the battery.

The starting motor includes the armature 4 mounted on the shaft 80, livebrushes l5, grounded brushes It, and field coils H. The usual gears orconnections (not shown) for engaging the fly wheel of the enginewhenever the starting motor is set in operation are provided. Theseconnections may be of any suitable type, but preferably in the form ofwhat is known as the Bendix drive, or a solenoid operated device forcausing the starting motor gear to engage the gear on the fly wheel.Both types are well known and need no further description.

The engine is-provided with a storage battery It which has one terminalgrounded and the other terminal connected by an electrical conductor l9thru the ammeter to the ignition switch terminals 2| and 22. Theignition switch is provided with a rotatable blade 23 which may beturned to the right with reference to Figure 1 for the purpose ofconnecting terminal 2| with the outlet terminal 24, or alternatively itmay be rotated to the left with reference to Figure 1 for the purpose ofconnecting together the terminals 22, and 26. Terminals 24 and 25 areconnected together by means of the wire 21 which in turn is connected bymeans of wire 28 to the primary coil 29 of the ignition coil. Theprimary coil 29 is grounded thru the breaker arm 30 thru which thecircuit is opened and closed by means of the rotating cam 3|. Acondenser 32 is connected across the breaker points to prevent excessivesparking. The secondary coil of the spark coil is indicated at 33 andthis is connected by means of the wire 34 to the distributor 35.

The current supply to the starting motor is controlled by a. switch 31which is operated by a solenoid 38. One terminal of the switch 31 isconnected to the electrical conduit [9 by means of a wire 39 and theother side of the switch 31 is connected to the starting motor by meansof a wire 40. The iron core 4| of the solenoid is normally held in theposition shown in Figure 1 by the coil spring 42, but when current ispassed thru the solenoid coil 38 the copper disk or switch 43 makescontact with both sides of the switch 31 simultaneously, thereby closingthe circuit for current to fiow to the starting motor.

The travel of the solenoid core4| and copper disk 43 is limited by meansof the bracket 44. The spring 42 and also the solenoid core 4| are soconstructed and arranged that more current is required to flow thru thesolenoid 38 to start the movement of the solenoid core to the left withrespect to Figure 1 than is required to retain it in that position, orin other words the further the solenoid core 4| projects out of the coil36 the more current has to fiow thru the coil in order to overcome thespring tension.

The terminal 26 of the ignition switch is connected by means of a wire45 to a resistance element which is preferably in the form of thefilament 46 of an electric light bulb 52. The nature of this resistanceelement is such as to pass a larger current when the filament is coldthan when it is hot, so that when the current is first turned on withthe filament cold a substantial amount of current may flow for thepurpose of operating a relay switch, but after the current has beenflowing long enough to heat the filament to incandescence, theresistance is increased so as to cause a substantial drop in theamperage. One terminal of filament is connected by means of a wire 41 toa switch 48 which may be operated by the accelerator pedal 49 or anyother suitable control device.

It is not absolutely necessary to include the switch 48 in the circuitand the connection 41 may be connected directly to the wire 5!] ifclesired. However, I prefer to include the switch 48 because thisinsures that the operator will depress the accelerator pedal to open thethrottle slightly before the starting motor is turned on. It will beunderstood that this is desirable particularly in starting the motorunder low temperature conditions.

The showing of Figure 1 is purely diagrammatic but it will readily beunderstood that the device indicated at 5| is a conventional carburetorhaving a throttle valve (not shown) mounted on shaft 53 which iscontrolled by opcrating lever 54 and some kind of linkage orconnections, such as indicated at 55 is provided for causing thethrottle valve 52 to open when the accelerator pedal 49 is depressed.

The wire 50 is connected to a solenoid relay switch having a housing 65which is mounted on or connected to the intake manifold of the engine insuch a manner as to be influenced but not completely controlled by thesuction conditions therein.

The solenoid relay switch will be best understood upon reference toFigures 3, 4 and 5 in which the reference character 56 indicates aterminal connected to the wire 50 and to one end of the winding of thesolenoid coil 51. The other end of the coil 51 is connected to theterminal 58 which in turn is connected by means of the generator.

take manifold 3.

slidably mounted with respect to the housing 65 and solenoid coil 51 andis normally held in downward position by the spring 66 separating thecopper disk or armature 63 from the terminals 62 and 56. The centralpart of the coil 51 is fitted to a tubular brass member 61 whichslidably receives the soft iron core 64 and the upper end of the tube 61is exposed to atmospheric pressure through an opening 68 formed in theend of the plug 69 in the upper end of the tube. The lower end of thesolenoid core is provided with a shaft 10 which is loosely received andguided by the bore 1| in the lower part of the base member 12. The basemember 12 is provided with suitable screw threads 13 which are adaptedto be screwed into the in- The suction of the manifold, if any, iscommunicated through passages 1| and 14 to the inside of the air tighthousing formed by the members 65 and 12, so that when ever suctionexists in the manifold the outside atmospheric pressure acting on theupper end or head of the slidable member 64 tends to move the member 64and the armature disk 63 clown-- Wardly to break the connection betweenterminals 56 and 62.

The terminalBZ is connected by means of a wire 13 to one end of thesolenoid coil 38.

The upper end of the soft iron plug 69 is provided with a screw threadedstem 15 which is received by corresponding threads in the housing member65 and which carries a lock nut 16, to hold it in adjusted position. Bysuitable adjustment of the lock nut and member 69 the magnetic gapbetween the member 64 and the member 69 may be adjusted so that theamount of current required to operate the device may be controlled. Anon-magnetic washer is inserted between the top of the core 64 and theplug 69 to prevent sticking.

The electrical connection 58 is connected to a terminal 11 mounted onthe end of the housing 18 which is attached to one end of the startingmotor. Inside the housing the terminal 11 is connected to an insulatedcontact member 19. The armature shaft of the starting motor is drilledand tapped to receive a screw 8| which carries a speed responsivedevice.

The speed responsive device comprising a sheet metal member 82 having acentral opening to receive the screw 8| and an upturned edge 83 toprevent the escape of the balls 64 which are normally held at the centeragainst the screw 8| by means of the dished member 85 which in turn isresiliently held by the coil spring 86. The member 85 is preferablyprovided with an integral guide member 81 coaxial with the screw 8| andslidably receiving the head 88 thereof.

In order to provide a delayed action for the operation of the relayswitch I connect an ordinary electric light bulb 89 between theconnections 50 and 60, so that when current is first turned on thefilament 90 is cold and acts as a shunt or short circuit which reducesthe flow of current through the solenoid coil 51. It takes about asecond or two for the filament 90 to heat up and become incandescent andduring this period the flow of current through the coil 51 isinsufficient to draw the solenoid core 64 upwardly against theresistance of the spring 66. However, as soon as the filament 90 becomesheated its resistance is increased and more current flows through thecoil 51 so that the armature 63 is drawn upwardly to connect theterminals 62 and 56.

2,068,484 In order to secure the best results the respective resistanceof the filaments and 46 are so constructed and arranged as to cause amore rapid heating of the filament 90 than of the filament 46. Thereason for this will be readily apparent in view of the fact that the.resistance element 46 allows the operation of the relay only before itis heated up while the function of the filament 90 is to preventtheoperation of'the relay 65 until after it is heated up.

In view of these facts the relay 65 would not operate at all if therewas not a time interval after the heating up of the filament 80 andprior to the heating up of the filament 46. The manner of constructingthese filaments to cause them to heat up in different time periods willbe readily apparent to those skilled in the art, but

briefly stated the filament 90 is preferably made smaller and shorterthan the filament 46.

In order to provide for manual operation of the starting motor whendesired, I may provide an ordinary push button switch 9| for connectingthe electrical conduit l8 directly with the terminal of the coil 38through the wire 82.

The operation of the device shown in Figure l is as follows:

In order to start the engine the operator turns the switch 23 to theleft to the position indicated in dotted lines in which terminals 22, 25

and 26 are made common by the switch blade 23. This supplies current tothe ignition system of the engine thru the wire 28 and the othermechanism illustrated in the upper central portion of Figure 1. Thismechanism may be of any conventional type. Current is supplied from theterminal 26 thru the wire 46 to the filament 46 and then thru wire 41 tothe switch 48.

In order to set the throttle valve in the best position for starting,the accelerator pedal 49 is depressed, thereby closing the switch 48 andpermitting the current to flow thru the wire 50 to the terminal 56 ofthe suction influenced solenoid operated switch 65 as indicated inFigures 3 and 4. The current now flows thru the solenoid coil 51 andmagnetizes the core 64 but when the current is first turned on thefilament 90 acts as a short circuit between the inlet and outletterminals 56 and 58 respectively of the coil so that the resistance ofthe spring 66 is 'not instantaneously overcome by the core 64. After ashort interval, however, varying from a fraction of a second to 1 or 2seconds, the filament 98 becomes incandescent and its resistanceincreases to such an extent that the current flow thru the coil 5! issubstantially increased so that the magnetic attraction of the core 64overcomes the pressure of spring 66 and the armature 63 is drawnupwardly against the terminals 56 and 62. It will be understood that thecurrent flows from the coil 51 thru the connections 59, 60 and (ii tothe terminal I l of the generator and thru the generator coil to theframe of the engine or other suitable ground so that the circuit iscompleted to the battery which also has one grounded terminal.

The terminals 56 and 62, having been connected by the disk armature 63current, can now fiow thru the conductors 13 and 92 to the soleenginesometimes one or two shots in the engine cylinders will be obtainedwithout getting a continuous run, thereby temporarily increasing-theengine speed to such a point as to cause the gear of the starting motorto disengage the fly wheel gear of the engine if these gears are of theBendix type; that is to say if the Bendix drive is used. If the gear ofthe starting motor becomes disengagedunder these conditions that is,when a continuous run of the engine is not obtained and the current tothe starting motor is not shut off, the speed of the starting motor willrapidly increase to a degree far beyond any speed at which it could everbe required to crankthe engine. This continued running of the startingmotor is not only damaging to the motor by reason of the excessive speedbut also prevents the proper functioning of the motor to re-crank theengine.

With an inexperienced operator the noise madeby the rapidly runningstarting motor may be mistaken for the normal running of the enginecausing confusion. in the mind of the operator, and eventually result ina total failure tostart the engine.

By means of the device shown in Figures 7, 8 and 9 the starting motormay be stopped and restarted automatically in such a manner as to causethe starter gear tore-engage the fly wheel gear when the motor isre-started. It will be noted that the balls 84 will be impelledoutwardly by centrifugal force. During normal cranking of the enginethis'force is not sufl'lcient to overcome the pressure of the spring 86and the balls simply remain in the position shown in Figure '7. However,when the starting motor attains an abnormal speed (as may occur when theengine starts to run under its own power but does not continue to doso") the centrifugal force is sufiicient to throw the balls outwardly tothe position indicated by dotted lines in Figure 9 and in Figure 10.

Due to the fact that the faces of the members 82 and are dish shaped,the balls do not return tq the center instantly when the speed fallsbelow that which is necessary to throw them to the outward position. Byproperly arranging the angle of the faces of the members 82 and 85'theballs may be made to remain at the outside of the circle and against themember 83 until the motor has practically stopped, at which time theyare returned all the way to the center against the screw 8|. It will beunderstood that radial grooves or partitions in! may be provided to keepthe balls from collecting at one side and thus throwing the device outof balance.

It will readily be understood that when the balls are thrown to theoutside against the rim 83 the member 8! will be moved to the positionshown in Figure 10, thus grounding the terminal 19 and the wire 50, towhich it is connected by means of conductor 36. This cuts oiT- thesupply of current to the solenoid coil 38 and permits the spring 42 tobreak the switch 31, causing the shafthas very little voltage during thefcranking 7 operation, so that there is no great resistance to the flowof current from the battery, thru the connections 50, 60, GI and II, andthe winding of the generator to the ground through the brush I2.However, when the engine starts to fire and run under its own power thecrank shaft speed immediately builds up and drives the generatoraccordingly, so that the generator voltage increases and bucks thecurrent flowing from the battery thru the generator coils to the ground.

It will be understood that the polarity of the generator and battery isso arranged as to cause the generator to feed back into and re-chargethe battery whenever the generator voltage is higher than the batteryvoltage. When the crank shaft speed reaches approximately 200 R. P. M.the generator voltage is suflicient to cut down the current flowing thruconductors in and 60 so much as to reduce the strength of the coil 61below that which is required to retain the core 64 in the position shownin Figure 3, and the spring 66 forces the core downwardly to theposition shown in Figure 4.

This position is retained as long as the generator voltage is maintainedat a sufilcient value to prevent the re-energizing of coil 61 from thebattery. In practice the voltage of the generator and the variousresistances of the system are worked out in such a manner as to preventthe re-engagement of the armature 63 with contacts 66 and 62 as long asthe engine maintains a speed not lower than the minimum speed at whichit will run under its own power.

In order to assist the spring 66 in keeping the relay switch fromclosing when the engine speed is lowered, the flexible gasket forms aseal with the disk armature 63 against which the suction existing in theintake manifold is applied. As long as the throttle is in closedposition no current can flow thru the relay 65 because the switch 48 isopen, as indicated in solid lines in Figure 1. When the'throttle valveis in open position the normal speed of the engine, and'the generatorvoltage will be high. The importance of the suction arrangement forassisting spring 66 to keep the armature 63 from contacting terminals 62and 66 lies in the fact that during sudden acceleration in high gearfrom very low speeds, and during some hill climbing conditions, thethrottle valve is held in open position while the engine speed is alsovery low. The suction in the intake manifold under these conditions isnot very high, but a very slight addition to the force holding thearmature 63 in the position shown in Figure 4 is suflicient as long asthe engine is actually running under its own power. When the relayswitch is in closed position, that is when the disk armature 63 is incontact with the terminals 56 and 62, the suction does not act on themember 63 but merely on the area of the core 64 which is much smaller sothat the suction has comparatively little effect. Also the core 64 israther loosely mounted in the solenoid so that there is a substantialamount of leakage which tends to reduce the suction.

It will be understood that when the engine speed reaches normal, say 350R. P. M. or more, the generator voltage is sufficient to operate thereverse current relay switch l3 connecting the conductor 6| with theconductor 96, thereby short-circuiting the filament 46 and conductors46, 41, 50 and 6D togetherwith the relay 65 so that the solenoid 38 cannot close switch 31.

If for any reason the operator desires to crank the engine withoutturning on the ignition switch 23, the push button switch 9| may beoperated to connect the conductor 92 direct to the battery lead I5. Itwill be understood that the provision of this switch is not absolutelynecessary but that it is an additional feature of convenience. Thisswitch is also useful in case of damage to any of the automaticmechanism such, for instance as the burning out of the filament 46 or90.

In case any of the starting mechanism fails in such a manner as to causethe starting motor to be operated while the engine is running, theswitch 23 may be moved from the left hand position to the right handposition with reference to Figure 1 after the engine has been started.This disconnects the terminal 26 from the battery and positivelyprevents the operation of the automatic mechanism for operating thestarting motor. With the switch 23 in its normal left hand position forstarting, action is completely automatic in that the starting motor willbe operated to start the engine when the ignition switch is turned on,disconnected when the engine has begun to run under its own power andagain operated whenever the engine stalls.

,In the simplified device shown in Figure 2 the suction is not used toinfluence the operation of the starting device. The bulb 52 is connecteddirect to the terminal 26 the same as in the construction shown inFigure 1, and the outlet of the bulb 52 is connected direct to the inletof the coils 38 by means of a wire IIJI. Instead of grounding the otherend of the coil 38 as is done in Figure 1, it is connected to the switch48 by means of a wire I02, and the other side' of the switch 48 isconnected direct to the conductor 6| by means of a wire I03. The switch48 is operated by the lever 49 which is connected to the throttle in themanner shown in Figure 1.

For simplicity of disclosure, the carburetor, throttle, and connectinglinkage are omitted from Figure 2. The bulb 69 is connected in. parallelwith the coil 38 so as to have a shunting or short circuiting actionwhen its filament is cold in the same manner in which it short circuitsthe relay switch 66 in the construction shown in Figure 1. One end ofthe conductor 36 is connected to the terminal 11 the same as in Figure1, and the other end is connected between the bulbs 52 and 89.

In order to provide some means of adjusting the system so as to causethe starting system to cut in at the exact point desired with referenceto the crank shaft speed, (in constructions in which the relay switch 65is omitted) I provide the adjusting screw I04 which is threaded into thebracket 44 and which limits the travel of the armature 3 under theinfluence of the spring 42. It will be understood that the magnetic gapbetween the solenoid coil 38 and the solenoid core 4| is increased inaccordance with the distance which the spring 42 is permitted to movethe armature 43 and the core 4| to the right with respect to Figure 2.It will be readily understood that the generator voltage in differentinstallations may vary, and the speed at which it is necessary tooperate 'the crank shaft to cause the starting mechanism to cut outwould vary correspondingly if the adjusting device I04 or its equivalentwere not provided. It will also be understood that the adjustment I04serves the same purpose as the adjustment which is provided for themember 69 shown in Figure 3.

The operation of the device shown in Figure 2 is as follows: When theswitch 23 is turned to the left to the position indicated in dottedlines,

current is supplied from the terminal 26 to the filament 46 as well asto the ignition system. This current flowing through conductor Ilil,coil 38, and conductor I02 to the switch 48, and, when the switch 48 isclosed, through the conductors I83, 6| and the coils of the generator tothe ground.

When the current is first turned; on, the filament 90 is cold, and thecurrent flows so freely through this filament as to prevent theoperation of the solenoid controlled switch 31-43. In a second or less,however, the filament 90 becomes heated, and its resistance increasessothat enough current is caused to flow through the conductor NH and thecoil 38 to close the switch 31-43. This closes the circuit tothestarting motor which immediately begins to crank the engine.

As soon as the engine begins to run under its own power, its speed willincrease and the generator voltage will build up to such a point as tocause a back pressure against current from. the battery, and the flowthrough the coil 38 will be out to such a pointas to cause the startingmotor current to be cut off at the switch 31. As soon as the enginereaches or exceeds a predetermined operating speed, switch l3 will beclosed, and the connections I 9--46-l0l38- llJ2-l83 will be shortcircuited by means of the conductor 96 so that there is no danger ofoperating the starting motor while the engine is in normal operation.

If the engine is operated at a very slow speed by reason of the operatorclosing the throttle, the switch 48 is cut off, and this prevents thestarting motor from being operated, even though the generator voltagemay be so low as to cause the switch l3 to be opened. If the engine isoperated at a slow speed by reason of a heavy load being applied to theengine, the throttle valve may be in open position and the switch 48 maybe closed. However, when the engine slows down under these conditions,the deceleration is gradual and the voltage drop of the generator. iscorrespondingly slow. Under these conditions, the filament 46 is heatedup before there is sufllcient current flowing from the battery to thegenerator to cause the operation of the starter switch 31. When thefilament 46 is once heated up, the starter switch can not be operated bycurrent flowing from the battery until and unless, the generator voltagedrops to practical zero.

It will be understood that by including sufficient resistance in thefilanTent 46, the starting system could be prevented from operating evenif the engine stopped altogether with the throttle in wide openposition. Also by properly calibrating the resistance of the filament46, the starting system can be made to cut in at any desired enginespeed. It will be understood that in connection with the device shown inFigure 2, the speed responsive device shown in Figures '7 to 10inclusive will operate to ground the starting system and cause it ,tostop and restart when conditions require it, the same as the deviceshown in Figure 1.

It will be understood that the speed responsive device may be entirelyomitted together with its connection 36, if desired. It will also beunderstood that the reason for including this device is to prevent thenecessity for knowledge on the part of the operator as to when theignition switch 23 to permit the starting motor to stop so that its gearcan be reengaged with the gear on the fly wheel of the engine.

With the speed responsive stopping device shown in Figures 7 to 10inclusive, no thought on the part of the operator is necessary to causethe starting motor to stop and restart. It is only necessary for theoperator to turn on the ignition switch and depress the acceleratorpedal 49 so as to open the throttle valve to the proper position forstarting.

The switch 48 together with its connections to the accelerator pedal maybe omitted if olesired. However, it is preferable to use this switch forthe following reason in addition to that previously stated. Frequently,automobiles are stopped at the curb and left in gear. This may be donefor several reasons, one of the most important being that the emergencybrake may not be in proper working order, or it may become accidentallyreleased, and if the operator leaves the gear shift lever in low gear,there is little chance of the car coasting off down a hill, even if theemergency brake is not set or not working for some reason. If the switch48 is omitted, a child may come along and turn on the switch key, andthat would be the only thing necessary to start the engine and theautomobile. Obviously, this could result in an accident. By includingthe switch 48, the engine will not start unless the accelerator pedal isdepressed with the ignition switch turned on. However, the switch 48 maybe omitted if desired, and the wire 50 permanently connected to the wire41 so that the action will be the same as if the switch 48 waspermanently held in closed position.

. For the purpose of making a simplified system, the bulb 89 and itsfilament 90 may be omitted, but its function will naturally be lost. Thefunction of this bulb is as follows: It frequently happens that when theoperator of an automobile comes to a stop sign, he will not bring thecar to a full stop, but will slow down to two or three miles an hour,leaving the car in high gear, and step on the accelerator pedal. Thiscauses a very substantial drop in generator voltage and might result inoperation of the starting system for a period of a fraction of a secondjust after the accelerator pedal is depressed. The delayed action causedby the short circuiting effect of the filament 90 is just suflicient toprevent the engagement of the starting motor under these conditions.

For the purpose of constructing an extremely simple system, the bulb 52with its filament 46 may be omitted and the terminal 26 may be connecteddirect to the switch 48 or the conductor 50' (in the construction shownin Figure 1) or to the conductor IOI (with reference to Figure 2). Ifthis is done, then the resistance of the coil 51 can be slightlyincreased or else the magnetic gap between the core 64 and the plug 69can be increased if the device shown in Figures 1, 3, and 4 is used.With the construction shown in Figure 2, the resistance coil 38 shouldbe somewhat increased or else the magnetic gap between the solenoid core4| and the solenoid should be increased by backing oif the adjustingscrew I04.

I claim:

1. In an internal combustion engine, a generator driven by said engine,a starting motor for said engine, a storage battery adapted to besupplied with current from said generator under certain conditions andadapted to supply current to said starting motor under certainconditions, connections including a reverse current relay switch forconveying current from said generator to said battery, connectionsincluding a starter switch for conveying current from said battery tosaid starting motor, a solenoid for operating said starter switch, saidsolenoid and said reverse current relay switch being connected inparallel between said generator and said battery, and a heat responsivevariable resistance in circuit with said solenoid.

2. In an internal combustion'engine, a generator driven by said engine,a starting motor for said engine, a storage battery, means includ-- inga reverse current relay switch for conveying current from said generatorto said battery, means including a starter switch for conveying currentfrom said battery to said starting motor, means including a solenoid foroperating said starter switch, said solenoid being connected to saidgenerator and to said storage battery, and a heat responsive variableresistance connected in parallel with said solenoid.

3. In an internal combustion engine, a generator driven by said engine,a starting motor for said engine, a storage battery, means including areverse current relay switch for conveying current from said generatorto said battery, means including a starter switch for conveying currentfrom said battery to said starting motor, means including a solenoid foroperating said starter switch, said solenoid being connected to saidgenerator and to said storage battery, by means including a heatresponsive variable resistance.

4. In an internal combustion engine, a generator driven by said engine,a starting motor for said engine, a storage battery, means including areverse current relay switch for conveying current from said generatorto said battery, means including a starter switch for convaying currentfrom said battery to said starting motor, means including a solenoid foroperating said starter switch, said solenoid being connected to saidgenerator and to said storage battery, and a heat responsive variableresistance connected in parallel with said solenoid.

5. In an internal combustion engine, a generator driven by said engine,a starting motor for said engine, a storage battery, means including areverse current relay switch for conveying current from said generatorto said battery, means including a starter switch for conveying currentfrom said battery to said starting motor, means including a solenoid foroperating said starter switch, said solenoid being connected to saidgenerator and to said storage battery, by means including a heatresponsive variable resistance, and a heat responsive variableresistance connected in parallel with said solenoid.

6. In a device of the class described, a starting motor, a solenoidcontrolled relay switch, a storage battery, a manually operated switch,connections from said manually operated switch to said solenoid, saidconnections including a heat responsive variable resistance, the voltageof said battery and the resistance of said solenoid being so calibratedwith respect to said heat responsive resistance element as to cause theoperation of said solenoid controlled switch when current is passedthrough said resistance element cold, but not when said resistanceelement is hot.

7. In an internal combustion engine of the type having a storage batteryhaving a live terminal and a grounded terminal, a generator mounted onand driven by said engine, said generator having a pair of terminals,one of which is grounded and the other of which is connected to one sideof a reverse current relay, an ignition system for said engine, anignition switch, a connection from said ignition switch to the liveterminal of said battery, a connection leading from the other side ofsaid reverse current relay switch to a point in the connection betweensaid ignition switch and said battery, a starting motor, connectionsincluding a solenoid controlled relay switch for conveying current fromsaid battery to said starting motor, a connection from said ignitionswitch to the live terminal of said generator, the winding of saidsolenoid controlled switch being included in said last named connection,and a heat responsive variable resistance also included in saidlastnamed connection.

8. In apparatus for starting an internal combustion engine, a startermotor, a battery, a starter circuit for electrically connecting saidmotor and said battery, and controlling means for said circuit includinga resistance unit of positive temperature coefilcient or resistance,said unit being constructed and arranged when hot to substantiallyresist initial actuation of said starter motor and when cold to permitthe passage of sufficient current therethroush to initially actuate saidmotor.

9. Apparatus as specified in claim 8 in which said circuit controllingmeans is in the form 0! an auxiliary circuit and further includes agenerator for producing current in said auxiliary circuit in oppositionto the battery current therein, said unit when hot being adapted tocooperate with current from said generator to prevent actuation of saidmotor, the resistance of said unit when hot or cold being ineflective toprevent operation of said motor without assistance from the generatorcurrent produced when the engine is running under its own power.

10. In apparatus for starting an internal combustion engine, a startermotor, a. source of current, a circuit for connecting said motor andsaid source, and control means for said circuit including a pair orvariable resistances of positive temperature coefllcient of resistanceand having different heating periods.

11. Apparatus as specified in claim 29 in which said control meansfurther includes a device responsive to the active or inactive conditionof the engine, said variable resistances being arranged in saidconnecting circuit so that sufllcient current for initially actuatingsaid motor can pass through said circuit only during the period afterone of said resistances becomes hot and before the other resistance hasbecome hot.

12. In apparatus of the class described, a starter motor, a source ofelectrical energy, a connecting circuit therebetween including groundingmeans constituting one side oi. said circuit, a manual switch in saidcircuit, a. grounding shunt connecting with said circuit between saidsource of energy and said motor, a switch in said shunt and a controldevice for said shunt switch associated with said motor and constructedand arranged to close said shunt switch to cut-oil" said motor when saidmotor exceeds a pre-determined speed.

13. Apparatus as specified in claim 12 in which said motor speedresponsive device and said grounding shunt constitute no part of theconnecting circuit between said starter motor and said source of energywhen said starter functions normally to crank an engine.

14. In a device of the class described, a starter circuit meansincluding a starting motor, a solenoid controlled relay switch, astorage battery, a manually operated switch, and connections from saidmanually operated switch to said solenoid, said connections including aheat responsive variable resistance, the characteristics of said circuitmeans including the resistance of said solenoid, the voltage of saidbattery and said heat responsive resistance being so calibrated as tocause said solenoid controlled switch to close when current is passedthrough said variable resistance and hold said solenoid switch closedafter said resistance becomes hot,

but to prevent the closing of said solenoid switch after said resistancebecomes hot.

IRVEN E. COFFEY.

CERTIFICATE OF CORRECTION.

Patent No. 2,068,484. January 19, 1937.

IRVEN E. COFFEY.

Page 6,

ass in the Patent Office.

Signed and sealed this 30th day of March, A. D. 1937.

Henry Van A rsdale (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2,068,484. January 19, 19

IRVEN E. COFFEY.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

